Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.6 (CAD)
 4,420 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

LV systolic function and dilation after Ml have been extensively studied and have been related to heart failure and cardiac mortality. In recent years, it has been increasingly apparent that LV diastolic dysfunction contributes to signs and symptoms of heart failure and LV diastolic dysfunction is associated with increased mortality rates in patients chronic heart failure independent of systolic function. LV diastolic dysfunction is difficult to assess on basis of clinical examination including chest radiography and electrocardiography. LV diastolic filling has traditionally been evaluated by cardiac catherization with direct measurement of filling pressures and relaxation. However, the invasive approach describing LV compliance and relaxation as the major determinants of LV diastolic function, is not feasible and suitable for routine investigations of diastolic function. Two-dimensional and Doppler echocardiography has become a well accented practical and safe non-invasive method for diagnosis of LV diastolic dysfunction. Combined invasive and echocardiographic studies have shown that analysis of mitral and pulmonary venous flow velocities relate to invasively measured filling pressures and relaxation rate in cardiac diseases. Based on Doppler analysis of mitral and pulmonary venous flow three abnormal LV filling patterns are identified: impaired relaxation, "pseudonormalization" and restrictive. These LV filling patterns have been related to symptoms, relaxation rate, filling pressure and prognosis in patients with restrictive and dilated cardiomyopathy. The Doppler flow profiles are influenced by several factors including age, heart rate, load conditions and valve heart diseases which must be taken into consideration during evaluation. During the last decade information about LV diastolic function assessed non-invasively by Doppler echocardiography has gained in patients with CAD. Myocardial ischemia induced by brief coronary artery occlusion or pacing leads to abnormal myocardial relaxation which can be reversed to normal by restoring normal myocardial blood flow. The diastolic abnormality is present within seconds and a characteristic impaired relaxation filling pattern are identified by mitral and pulmonary venous flow analysis. Diastolic dysfunction has been recognized during the early as well during the post-MI phase with or without LV systolic dysfunction. In the acute phase both an abnormal relaxation pattern and restrictive LV filling pattern are present which has been related to in-hospital heart failure. The identification of a pseudonormal or restrictive LV filling pattern are associated with later readmission to hospital with heart failure and cardiac death. Abnormal relaxation filling is the most pronounced filling pattern after one year which might be related to the remodeling process including compensatory hypertrophy, scarring of the infarct zone leading to a non-uniform relaxation of the LV. Remodeling of the LV following a MI is subject to several factors which might involve diastolic function. This is supported by the presence of an impaired relaxation and restrictive filling pattern are associated with progressive LV dilatation following Ml. Furthermore, the LV remodeling process following the very early phase includes the scarring process with collagen deposition in the infarcted and non-infarcted myocardium. The extent and quality of the repair process involving collagen deposition are believed to influence the remodeling process. Increased collagen deposition in the subacute phase of Ml indicated by elevated values of the collagen marker PIIINP is found to be related to LV dilation, depressed systolic function and restrictive LV filling. Development of a restrictive filling in patients with increased collagen deposition might be due to increasing LV volume but also to increased myocardial stiffness. Regarding prognosis diastolic dysfunction seems to be an important marker of outcome as abnormal diastolic properties are related to progressive LV dilatation, development of heart failure and cardiac death following MI. The beneficial effects of BB on morbidity and mortality in post-MI patients are well established. Recently, it has been demonstrated that BB has beneficial effects on progressive CHF and cardiac mortality in patients with chronic heart failure and moderate to severe systolic dysfunction. The mechanisms behind these effects are not fully understood. However, improvement of both systolic and diastolic function during BB therapy are demonstrated in patients with CHF. A few studies in patients with MI indicates that long-term BB therapy improves LV diastolic function which seems to be followed by improvement in systolic function. BB has the potential to lengthening diastole, improving subendocardial myocardial perfusion and affecting symptomatic amd neurohumoral activation following MI which might affect LV systolic and diastolic function and thereby improving outcome. Functional capacity following Ml is a well known predictor for outcome in MI patients. LV diastolic function a closely related to exercise capacity in contrast to measures of systolic function. BB therapy in patients with mild to moderate systolic dysfunction seems to improve exercise capacity which is related to improvement in LV diastolic function. Thus, BB improves exercise capacity and diastolic function by increasing LV compliance which might have prognostic implications. Even though LV systolic and diastolic dysfunction coexist, few two-dimensional and Doppler echocardiographic variables combine measurements of both phases of the cardiac cycle. Recently, the MPI has been suggested as a measure of combined systolic and diastolic myocardial performance which is based on Doppler time intervals of the systolic and diastolic phases. The MPI is easily obtained, reproducible, non-geometric and seems less dependent on heart rate and load conditions compared to traditional Doppler measurements. In patients with MI is has shown to reflect disease severity and contain prognostic information. The assessment of MPI seems therefore to be a relevant attractive alternative to established measurements of LV function following MI.
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PMID:Clinical aspects of left ventricular diastolic function assessed by Doppler echocardiography following acute myocardial infarction. 1176 25

Angina is a common symptom in patients with AS with or without accompanying CAD. When due to the valvular obstruction alone, the pathophysiology involves mismatch between reduced diastolic coronary flow and increased LV mass, or impaired coronary vasodilator reserve. When CAD is present, the severity of angina correlates with the extent of CAD, which tends to be inversely related to the degree of valvular obstruction at presentation. It is important to make a correct diagnosis of CAD in AS patients pre-operatively, since this factor significantly influences peri-operative morbidity and long-term survival. Whether MPI in AS patients can completely exclude CAD and eliminate the need for coronary angiography is a difficult question. Approximately 350 AS patients having had MPI have been reported. The studies differ in terms of scintigraphic technique (planar versus SPECT), stress modality, isotopes used, and definitions of an abnormal scan and what constitutes hemodynamically significant coronary stenosis. The 'best case' diagnostic data showed sensitivity of 87%, specificity 72%, positive predictive value of 81%, and negative predictive value of 86%. These figures indicate a high degree of accuracy and are comparable to the results of MPI in patients without AS. However, the data suggest that the diagnosis of coronary disease is missed by MPI in 14% of AS patients with CAD. Review of the referenced series indicates that in many cases, the stenoses were hemodynamically significant, and were important to identify pre-operatively to avoid operative morbidity and improve long-term prognosis. Thus, in conclusion, although MPI is highly accurate in AS patients, a normal study cannot totally exclude the diagnosis of CAD. Coronary angiography should continue to be performed, particularly in patients with angina, or who are at risk for CAD because of their risk factor profile.
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PMID:The value of myocardial perfusion imaging for diagnosing coronary artery disease in patients with aortic valve stenosis. 1206 Sep 24

This was an observational study carried out in the department of cardiology. Bangabandhu Shikh Mujib Medical University (BSMMU), Dhaka in collaboration with Institute of Nuclear Medicine (INM), Shabag, Dhaka during the period October 2002-March 2003. A total of 54 patients presenting with Canadian Cardiovascular Society (CCS) class I-II severity of chest pain with mean +/-SD age 49.88 +/- 8.44 yrs and having male to female ratio 5.75:1 were included in the study. The main objective of the study was to predict severity of myocardial ischemia by Exercise Tolerance Test (ETT) determined by Duke Treadmill Score (DTS) and by perfusion pattern observed following Single-Photon Emission Computed Tomography myocardial perfusion imaging (SPECT-MPI). All patients underwent ETT and then SPECT-MPI scan using Tc-99m-tetrofosmin in one-day stress and rest protocol. Coronary angiogram (CAG) was done with in six months of the perfusion study. After performing ETT, patients were categorized by DTS and myocardial perfusion studies were also stratified according to severity of perfusion defect. The formula used to calculate the score was: Exercise time- (5 x ST segment deviation)-(4 X Treadmill angina index). The angiographic findings (significant >50% stenosis) and perfusion defects in MPI were compared with the severity of DTS. There were 31 patients who had CAG proven (>50% luminal diameter narrowing) CAD and 23 patients free of CAD. After ETT patients were categorized by Duke Treadmill Score into high DTS 12 (22.22%) patients, intermediate DTS 20 (37.03%) patients low DTS 22 (40.74%) patients. In high DTS group 91.66% patients had perfusion defect, whereas in intermediate and low risk group it was 60% and 40.9% respectively. In high DTS group 91.66% of patients had angiographicaly proven CAD, 58.33% of them had triple vessel disease (TVD) while in intermediate and low risk groups angiographically proven CAD were 65% and 22.72% of whom TVD only in 15% & 0% respectively. The results of ETT using DTS score were satisfactorily correlated with SPECT-MPI scanning in high DTS subsets of patients only. It is therefore, suggested that patient of high risk DTS do not need for myocardial perfusion imaging study and should undergo CAG for further evaluation. But the intermediate and low risk groups were needed myocardial perfusion imaging study to guide for further evaluation.
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PMID:Role of exercise tolerance test (ETT) and gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) in predicting severity of ischemia in patients with chest pain. 1668 38

Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8 countries worldwide. CT has the potential to assess both anatomy and physiology in a single imaging session. The co-primary aim of the CORE320 study is to define the per-patient diagnostic accuracy of the combination of coronary CTA and myocardial CTP to detect physiologically significant coronary artery disease compared with (1) the combination of conventional coronary angiography and SPECT-MPI and (2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD.
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PMID:Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography: design and implementation of the CORE320 multicenter, multinational diagnostic study. 2214 96

This study was aimed to analyze the value of the SPECT MPI to myocardial ischemia and cardiac function parameters in the CAD prognosis assessment. A total of 890 patients with suspected CAD underwent adenosine loading stress gated SPECT. At a mean follow-up of (2.3 +/- 0. 4) year, a total of 37 adverse events occurred, including 12 cardiac deaths and 25 nonfatal myocardial infarctions. Univariate Cox analysis showed that diabetes (wald 6.95, P < 0.01), SSS (wald 24.31, P < 0.001), EF (wald 17.14, P < 0.001), ESV (wald 8.58, P < 0.01) and EDV (wald 7.95, P < 0.01) were significant predictors of MACEs. Multivariate Cox analysis showed that SSS (wald 6.69, P < 0.05) and EF (wald 4.70, P < 0.05) were independent predictors. According to the results, SSS and EF are both independent predictors of MACEs.
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PMID:[Diagnostic value of left ventricular function after adenosine loading detected by gated myocardial perfusion imaging for prediction of major adverse cardiac events]. 2445 60